Valid opinions are things like "Trump should have won a second term." I disagree, but if you think that's how the world should be, fair enough - I can't change your values for you.
But things like "Trump can still win a second term - it's not over yet" are NOT things that should be given a fair shake. That's nonsense. It is over. There's no evidence that the results of the election will ever be overturned. That's not expressing an opinion they have a right to, that's looking for an excuse to insert their view of the world in lieu of the process that's been establish for a long time that decides who gets to be in charge.